When the precoating method, which is used in inlay restorations, is applied to crown and bridge restorations, there are some problems in the direct manufacture of a temporary crown. This study investigated the effect of resin separators in building selfcuring acrylic resin (Unifast II, GC), assuming that a temporary crown is made directly on the tooth surface precoated with adhesive resin (Liner Bond II, Kuraray), and the effect of its residue on the adhesion of a luting cement (Panavia 21, Kuraray). All specimens were evaluated by the shear bond test and SEM observation of the fracture surface. Vaseline (Yakuhan), Tokuso Resin Separator (TOKUYAMA), Oxyguard (Kuraray), and Oxyguard II (Kuraray) were used, as the resin separator. The results were as follows.
(1) Between the separators used in this study, Oxyguard was the most effective separators for clinical use.
(2) The separation effect of Oxyguard dependend on polyethylene glycol, which is the main component of Oxyguard.
(3) The residue of Oxyguard on the precoated surface reduced the bond strength to Panavia 21, although this effect could be'eliminating by washing the residue off with running water for 30s.
View full abstract